a(n) = round( 2^n/n ).

Terms

a(0) =2a(1) =2a(2) =3a(3) =4a(4) =6a(5) =11a(6) =18a(7) =32a(8) =57a(9) =102a(10) =186a(11) =341a(12) =630a(13) =1170a(14) =2185a(15) =4096a(16) =7710a(17) =14564a(18) =27594a(19) =52429a(20) =99864a(21) =190650a(22) =364722a(23) =699051a(24) =1342177a(25) =2581110a(26) =4971027a(27) =9586981a(28) =18512790a(29) =35791394